Package for plastic material



Sept. 5, 1939. c. A. NELSON PACKAGE FOR PLASTIC MATERIAL FiledAug. 28, 1956 Patented Sept. 5, 1939 UNITED STATES PATENT oFFiEcE 2 Claims.

This invention relates to packages for plastic materials similar to the material known as Dentocoll, a reversible hydrocolloid used for taking impressions in the mouth for dental Work and which can be heated to a jelly-like consistency, kneaded, cooled and then reheated if necessary without reducing its impression-taking qualities. This plastic material, which is semi-rigid when cooled, has a high water content which must be preserved until the material is used, and in preparing the material for use it must be heated to render it suiciently plastic, and then kneaded to form a smooth, homogeneous mass.

Elcient packaging of such a material presents many complicated problems in that the package must be moistureproof to preserve the water content, the package must be capable of withstanding a relatively high temperature and remaining immersed in boiling water for long periods of time without being destroyed or weakened, and it must be of durable and pliant material so that the plastic material enclosed thereby may be subjected to the necessary kneading before it is extruded or otherwise removed from thek package.

Further, since the impression material is occasionally used a portion at a time, the package or container should be capable of being repeatedly subjected to the above operations without deteriorating, and during the periods of nonuse should provide a hermetic seal for the contained material.

U. S. Patent No. 1,977,580 relates to a package for a reversible hydrocolloid as above described and discloses a container of Celluloid which may, if desired, be enclosed within wax paper, Wax, or glass.

The package or container of the present invention is an improvement over the Celluloid package disclosed in the above patent and more specifically provides a container or coating of latex.

The present invention possesses many improvements over the Celluloid container of the above patent, and among them may be mentioned: a smaller, though equally durable package is provided, which occupies less space; the hydrocolloid is completely protected from escape of moisture in contrast with the ineectiven-ess of Celluloid for this purpose; the package is practically age proof; and the weight of the package is considerably less, thereby reducing shipping costs.

In addition to the foregoing, the package of the present invention has many additional ob- (Cl. 20G-46) jects and unexpected advantages over the above mentioned patented package and other prior art packages, chiefly, the latex package requires no coating of additional substances to render it moistureproof and durable and its use conse- 5 quently is not attendant with the removal of wax paper, wax or a glass casing, as heretofore; the latex container will withstand more abuse during heating or boiling, mixing and cooling the hydrocolloid mixture; no cemented joints are nec'- l0 essary which are likely to crack and permit the escape of moisture; there is no danger of the cemented portion or other cap being blown off by inside pressure from the hydrocolloid mixture when the same is heated; the removable latex 15 cap contemplated in a modied form of the present invention permits the mixture remaining unused to be effectively resealed; and the removable cap further permits opening of the package to add water to the hydrocolloid mixture to change 20 the consistency thereof, if desired.

The latex container or package possesses the additional advantage that it is less expensive to provide than prefabricated Celluloid tubes or packages or containers of other known materials 25 having the requisite characteristics and the further advantage that the packaging of the hydrocolloid material in latex is greatly facilitated in that fewer steps and less labor are required than when packaging the same in other materials. 30

For a more particular understanding of the present invention, reference is had to the accompanying drawing wherein:

Figure 1 represents a vertical and axial section of one form; 35 Figure 2 is a similar section of a modied form also employing the principles of the invention;

and

Figure 3 is a similar section of a further modification. 40

In each figure, A is the mass or stick of plastic material which inFig. 1 is provided with a continuous coating Il) of latex. Fig. 2` represents a modified form of the invention wherein a latex coating I0 is applied to the Celluloid 45 container of Patent No. 1,977,580. In Fig. 3, the latex container or coating is provided in two sections, the larger body portion i2 thereof carrying at its mouth a ring I4 provided with a ange I6. In this modication oi the invention, the 50 opposed end of the plastic material A is enclosed by a cap I8 of prefabricated rubber or otherwise formed as hereinafter suggested, which cap securely engages iiange i6 of the ring I4, thereby providing a hermetic seal for the plastic 55 material. Ring I4 is adapted to loosely t and be slidable upon the stick of plastic material so that, as portions of the material are used at divers times, the material may be progressively passed through the ring While the ring may be maintained in position to receive the closure cap during periods of non-use. The modified latex jacket of Fig. 3, instead of being applied directly to the plastic material as illustrated, may, if desired, be applied to the Celluloid container II of Fig. 2.

The latex container above described may be produced in any convenient manner and may, if desired, be fabricated as a coating applied directly to the hydrocolloid material. A suggested mode of manufacture comprises suspending the hydrocolloid stick in liquid latex by means of a wire pushed into the exposed end of the stick, the Wire having a hook at the free end thereof which may engage a suitable support While the stick is suspended in the latex and also While the coated stick is suspended in the air to permit drying of the latex. After the coating of latex of the desired thickness has dried, the suspending Wire may be Withdrawn from the stick of hydrocolloid material and the aperture formed in the coating by the Wire patched with latex. The liquid latex may not necessarily be heated, normal or room temperature being satisfactory for ordinary purposes. The character and concentration of the liquid latex solution is not ordinarily critical, various different compositions, concentrations and consistencies thereof having been employed with thoroughly satisfactory results.

In constructing the modification of the invention exemplied in Fig. 3, the ring I4 may be inserted over the stick A to a point near the upper end thereof and the stick then suspended in the latex up to and covering flange I6 of the ring. When the stick is removed from the latex bath and chied, the resulting coating I2, in addition to covering the portion of the stick submerged, is securely cemented to the ring I4. A strip or coating of suitable separating material may then be placed around the outer surface of the ring 'I4 and the exposed end of the stick A submerged in the liquid latex up to a point sufficient to cover the projecting flange I6. On withdrawal and drying, a closure cap I8 of latex is thereby provided, the mouth of which securely engages the flange I6 to thereby complete the package and hermetically seal the plastic material and the closure cap I8 may be removed and replaced as often as desired.

The preferred forms of the invention herein illustrated and described are not to be regarded as limiting the broad scope of the invention as defined by the following claims.

Having described my invention, I claim:

l. A package of plastic material comprising a stick of semi-rigid reversible hydrocolloid, a loosely tting flanged ring intermediate the ends of the stick, and end closures for the stick formed from latex, each of said closures engaging said ring and being secured together thereby.

2. A package of plastic material comprising a stick of semi-rigid reversible hydrocolloid carrying a slidable ring intermediate its ends, a coating of latex extending continuously over one end of the stick and over a portion of the ring and a removable closure for the other end of the stick engaging said ring.

CLYDE A, NELSON. 

